美味牛肝菌降低泡菜中亚硝酸盐含量的研究

亚硝酸盐是泡菜发酵过程中产生的一种有害的副产物。首次发现美味牛肝菌Boletus edulis子实体能显著降低泡菜中亚硝酸盐的含量。在实验组原料中加入新鲜美味牛肝菌子实体时，发酵第4天亚硝酸盐含量可降低97.1%。当泡菜中冷冻保藏的美味牛肝菌子实体的加入量分别为10%、20%、30%、40% 和50%时，发酵第4天对应的亚硝酸盐含量比不加美味牛肝菌的对照分别降低了20.9%、51.6%、93.9%、96.1% 和96.9%。发酵第6天开始亚硝酸盐含量降低百分比逐渐减小，发酵10d以上实验组和对照组中亚硝酸盐含量趋于一致，但此时的泡菜酸度增加、质量降低。此外，新鲜的和冷冻的美味牛肝菌子实体降低泡菜中亚硝酸盐的活性最高，常温晾干的活性次之，高温烘干的美味牛肝菌子实体没有降低亚硝酸盐的活性。

Effect of Boletus edulis fruiting body on reducing the nitrite content in pickles

The content of nitrite, a harmful by-product produced in the process of making pickles, could be reduced when Boletus edulis fruiting body was co-fermented with radish bulbs. When fresh B. edulis fruiting bodies were added to the crude materials, as compared with the control, the nitrite content in the pickles decreased by 97.1% on the fourth day. When frozen B. edulis fruiting bodies increased by 10%, 20%, 30%, 40% and 50%, the nitrite content in the pickles correspondingly decreased by 20.9%, 51.6%, 93.9%, 96.1%, and 96.9% respectively on the fourth day. From the sixth day the reduction of nitrite content gradually became retardant. In ten days the nitrate content of experimental groups and control group became nearly similar, while the quality of pickles became worse simultaneously. Fresh and frozen B. edulis fruiting body had the highest nitrite reduction activities, and the room-temperature dried one was second-best, while high temperature baking one showed no nitrite reduction activities.